Early symptoms of pneumonia in infants include coughing and fever, and some infants may have a slow onset or may not even show early symptoms. Pneumonia is a major common childhood illness, especially in infants and young children. It is caused by viral, bacterial and mycoplasma infections. Early symptoms of pneumonia in infants include fever, cough, refusal to eat or vomit, lethargy or irritability, and shortness of breath. The onset of the disease may be preceded by a mild upper respiratory tract infection for several days. Early body temperature is mostly 38-39 ℃, or up to about 40 ℃, mostly flaccid or irregular fever. Refusal to eat, choking, vomiting or dyspnea are mostly common in weak infants. However, some infants may not show early symptoms. Early pneumonia in infants may be accompanied by erythrocytosis, hypocalcemia, and hypoglycemia, and may even be associated with multiple organ dysfunction. Therefore, infants with early symptoms of pneumonia or suspected pneumonia should be hospitalized and treated promptly.